It's a full world they've got going at Arrow, which may be one of the reasons the show seems to have caught on with fans of the comics in ways the more hyped Agents of S.H.I.E.L.D. has not. In this repeat, A.R.G.U.S. (a secret government agency) is after Diggle, who is after the supervillain Deadshot (guest star Michael Rowe). When the trail leads to Moscow, Diggle, Felicity and Oliver hop on a plane to Russia, and end up with an uninvited guest in Isabel (Firefly's Summer Glau).

You can stage your own Firefly reunion by pairing Arrow with TNT's run of Nathan Fillion's ABC mystery/comedy hit. Plus, if you're still peeved at the latest season finale, you may enjoy revisiting the much better first one, which airs at 9 and is followed by the second-season premiere at 10.

The Goldbergs | ABC, 8:30 ET/PT

The family celebrates Halloween in a repeat that showcases the best and worst of this young sitcom as it worked to find its creative way. The story for the youngest child, Adam, while standard, is effectively sweet— but the story for Barry and his mother Bev (Wendi McLendon-Covey) leans uncomfortably on the comedy of intense humiliation. Only McLendon-Covey's talent and commitment save the scenes from tanking the episode, but she has to work far harder than she really should.